import java.util.Arrays;
public class ArrayUtils{
//1.计算数组中最大指
public static int arryMaxElement(int[] date){
int[] tmpArray = new int[date.length];
System.arraycopy(date,0,tmpArray,0,date.length);
java.util.Arrays.sort(tmpArray);
System.out.print("原数组最大值是");
System.out.println(tmpArray[tmpArray.length-1]);
return -1;
}
//2.计算数组中最小值
public static int arrayMinElement(int[] date){
int[] tmpArray = new int[date.length];
System.arraycopy(date,0,tmpArray,0,date.length);
java.util.Arrays.sort(tmpArray);
System.out.print("原数组最小值是");
System.out.println(tmpArray[0]);
return -1;
}
//3.计算数组值之和
public static int arrayElementSum(int[] date){
int sum = 0;
for(int i = 0; i < date.length;i++){
sum += date[i];
}
System.out.print("原数组和是");
System.out.println(sum);
return -1;
}
//4.数组拼接
public static int[] arrayJoin(int[] a, int[] b){
int[] tmpArray = new int[a.length];
System.arraycopy(a,0,tmpArray,0,a.length);
tmpArray = Arrays.copyOf(tmpArray,(tmpArray.length+b.length));
System.arraycopy(b,0,tmpArray,a.length,b.length);
System.out.print("两数组拼接后");
printArray(tmpArray);
return null;
}
//[start, end)5.数组截取
public static int[] arraySub(int[] date, int start , int end){
int[] tmpArray = new int[end-start];
int j = 0;
/*for(int i = start; i < end;i++){
tmpArray[j] = date[i];
j++;
}*/
System.arraycopy(date,start,tmpArray,0,end-start);
printArray(tmpArray);
return null;
}
//数组打印
public static void printArray(int[] temp) {
for (int i = 0 ; i<temp.length; i++) {
System.out.print(temp[i]+" ");
}
System.out.println();
}
//7.数组反转
// 比如:[1,2,3,4] => [4,3,2,1]
public static void printReversal(int[] date){
int[] tmpArray = new int[date.length];
for(int i = 0; i < date.length;i++){
tmpArray[date.length-i-1] = date[i];
}
printArray(tmpArray);
}
public static void main(String[] args){
int[] date = new int[]{1,24,34,45,5,6};
int[] dest = new int[]{77,44,44,5,5};
System.out.print("原数组date是 ");
printArray(date);
System.out.print("目标数组dest是 ");
printArray(dest);
arryMaxElement(date);
arrayMinElement(date);
arrayElementSum(date);
arrayJoin(date, dest);
System.out.print("start = 2 ; end = 5 输出是 ");
arraySub( date, 2 , 5);
System.out.print("反转原数组后 ");
printReversal(date);
}
}